GARDINER – The beach at Lake Minnewaska opened this season to swimmers just in time for the Fourth of July, however the shallow area will stay closed due to leeches, park officials said.

"There are small leeches in Lake Minnewaska. We found them when we put docks in the water and set up the beach; some staff got some leeches on them, that's how we found out about them," park manager Eric Humphrey said.

The park, which is run by the state Department of Parks, Recreation and Historic Preservation, tried to get rid of the leeches with traps, which didn't work, he said.

Then, through its environmental management bureau in Albany, it got a state Department of Environmental Conservation permit to hire a licensed applicator to administer a treatment of copper sulfate, he said.

The lake was completely shut down for two days after the treatment, which has not been effective, he said.

It re-opened Thursday to boaters, scuba divers and long-distance swimmers.

The beach area opened to swimmers the first time this season Friday, he said.

It had been scheduled to open Father's Day weekend, June 14.

"We've been working on this the last two weeks," he said.

Leeches are not dangerous to human health, he said.

"They're more of a pest, so we decided to open the beach. The shallow area will be closed," he said.

Leeches mate in the spring.

Freshwater leeches can be found in lakes, ponds, springs, streams or marshes, according to the DEC.